With the recent popularization of portable electronic devices such as cellular phones, notebook-size personal computers, and video camcorders and also vehicles such as hybrid electric vehicles, there is an increasing demand for batteries to be used as drive power sources of the above devices and vehicles.
Those batteries include a winding type battery produced by winding a positive electrode plate and a negative electrode plate while interposing a separator therebetween. For instance, Patent Literature 1 discloses a battery (a winding type battery) provided with a spiral type electrode body (a winding power generation element) that includes a center pin in which a cotter pin supporting one end of a separator is inserted, the separator being extended from a slit of the center pin, and a strip-shaped positive electrode (a positive electrode plate) and a strip-shaped a negative electrode (a negative electrode plate) being wound around the center pin while interposing the separator therebetween.
In this winding type battery disclosed in Patent Literature 1, the separator extending from the slit of the center pin in a radially outward direction is bent at almost right angle to extend along a peripheral surface of the center pin and then wound around the center pin.